RANKED: The 13 most popular Netflix original shows

"Stranger Things" is in the top five of Netflix's most popular shows.Netflix

Netflix famously — or infamously — keeps its viewing numbers under lock and key, which has ironically opened all kinds of doors to quantifying which shows are standing out on the streaming service and which ones are fizzling out.

As Netflix continues to flood viewers with new programming, it's interesting to see which original shows viewers are most interested in and talking about. That's where social-media research firm Fizziology comes in. It specializes in collecting social-media data and advising its entertainment clients on what people want.

Fizziology measured the first week of Twitter activity for Netflix's original programming and revealed the shows that are generating the most buzz here in the US.

There were some surprising results and insights from the data, such as how well its new YA series, "13 Reasons Why," ranked, and which Marvel show was the only one to make the list. Also, it looks like Netflix's push into reality TV is paying off.

Here's a look at the most popular shows based on social-media activity on Netflix: